What kind of website?
-If you mean hubs, you can't.
-If you mean a blog, put it into a html sidebar gadget/widget
-If you mean a real website, it has to be put in the layout's source code. If you've done your own layout, you should already know. If someone else did the layout, maybe it's best to ask them as putting a random widget can seriously mess up a layout when not placed properly.